Conveyor stub idler apparatus

ABSTRACT

Stub idler units for a flexible sidewall belt conveyors support the return belt run. Each unit includes a stub roll fixed to and forming an integral part of a solid shaft. A pair of re-lubricable, sealed bearings are mounted within opposite ends of a tubular bearing housing secured within a tubular mounting bracket. The shaft is journaled in the bearings clamped to the housing by a locking nut on the shaft end. A lubrication passageway is formed in the mounting bracket and housing and provided with a lubrication fitting. The passageway connects to the chamber between the bearings lubricating the bearings. A flexible hydraulic grease line is attached to the far side mounting bracket in place of the grease fitting. The grease line extends across the conveyor belt to the near side of the conveyor and terminates in a grease fitting for re-lubrication of the far side stub idler. The line is supported at the two mounting brackets by suitable shaped support elements mounted to the mounting brackets.

This is a continuation-in-part of Ser. No. 110,689 and filed Oct. 20,1987 now U.S. Pat. No. 4,844,241 by William S. Woodward and entitledCONVEYOR STUB IDLER ROLL APPARATUS.

BACKGROUND OF THE PRESENT INVENTION

This invention relates to a conveyor stub idler apparatus andparticularly to a stub idler including a roll for edge support of thereturn run of an endless flexible sidewall conveyor belt handlingparticulate matter and the like.

The movement of industrial products in the form of particulate andfibrous materials has for years been conveniently done with trough-typebelt conveyors operating horizontally or at inclines to 20 degrees. Theconveyor consists of a middle support structure with two or threeinclined rollers (idlers) located every four to five feet along the topor "carrying side" of the frame in the order to form the belt into atrough. As fully discussed in the copending parent application, theidler bearings operate in relatively severe conditions and arepreferably periodically lubricated in order to insure that the rollersturn and prevent belt damage. Of equal importance, however, thelubricant desirably purges the bearing seals of foreign matter caused bythe congealing of the grease as it cools when the conveyor is shut down,drawing in the dirt to the bearing surfaces and the like. The idlerstructures of the prior art are described in the above application,which discloses an improved cantilevered lubricated idler for thesidewall conveyors in which the conveyor may run horizontally, turningup at steep angles (to 90 degrees or vertical) and then turning oncemore to the horizontal position to discharge. The cantilevered shaftdesign increased the shaft bending wovement. As a result, the industrystandard shaft diameters (CEMA Rated) could not be used. Where thestandard was used, the axial lubrication passageways were eliminatedfrom the shafts, and the stub idlers were provides as "sealed for life",in place of the relubrication system. Prior art stub idler units alsoused conventional mounting arrangements, which provided for no "crossbelt" adjustment. Therefore, the shafts were threaded and held in placeby lock nuts on each side of the support bracket. However, adjustmentwas soon lost due to material build up and corrosion.

Although the device or the mounting or the stub idler apparatus shown inthe parent application provides an improved stub idler unit mounting andbearing support, in certain applications the use of the axiallyapertured shaft did not provide a total desired support for the heavycantilevered load encountered in such applications. An enlarged shaftstructure was required and thus requires special construction andmounting. Generally, the trade prefers a structure which uses thestandard diameter shaft.

Further in the conveyor apparatus to which the present invention isused, the stub idler rolls on the opposite sides of the conveyor aredesirably periodically lubricated. With the vertical orientation of theconveyor, many of the stub idler units are above ground level. A stairand platform is generally provided adjacent one side of the conveyor forappropriate maintenance and servicing in normal usage.

Because of the high angle capability of these conveyors, the conveyorsare generally include an inclined portion at an angle of between 45° and75° and, conventional walkways are replaced with more expensivestairways or ladders and platforms to one side only of the conveyor. Toduplicate the structure would be costly.

Servicing to the opposite or far side therefore generally requires theuse of a special equipment. The inventor realized it would be desirableto provide a system for appropriate lubrication of both the far and nearside stub units from the near side of the conveyor.

SUMMARY OF THE PRESENT INVENTION

The present invention is particularly directed to a conveyor stub idlerunit for flexible sidewall belt conveyors, as disclosed in the parentapplication, in which the bearings are similarly mounted in a bearingmount bracket with an improved lubrication system permitting use of asolid shaft.

Generally, in the present invention, a cantilevered stub idler unitincludes a solid shaft journaled in re-lubricable, sealed bearingssecured within a closed mounting bracket unit to support the roll shaftand idler roll for rotation. In accordance with the teaching of thepresent invention, the mounting bracket unit, which preferably includesa tubular bearing housing fixed within a tubular mounting bracket, isprovided with a fixed grease coupler to permit periodic lubrication ofthe bearings, and also permitting an interconnection of the greasecoupler of the idlers on the opposite sides of the conveyor from oneside of the conveyor. A channel or passageway is drilled in the mountingbracket and housing at a point midway between the two roller bearings.The passageway can be fitted with a grease fitting for relubricationfrom each side and fitted with hydraulic grease line for "one side"lubrication. In the far line connection, the grease line is threadedthrough support grease line brackets which are secured to a bracketmounting plate of the mounting bracket with the line extending under theconveyor belt. A thin wall tubing may be secured between the grease linebrackets to protect the line. The fresh grease can thus be fed from oneside between the bearings and permits re-lubrication from the rear side.

The passageway in any bearing assembly can of course also be plugged fora "sealed-for-life" design.

With the fixed external lubricating system fixedly mounted to thetubular supports, a cross lubrication system can be employed to permitlubrication from the stair side of the conveying mechanism of theconveyor. In the cross lubrication system, the mounting bracket to theopposite or far side from the stairs has a hydraulic line connected by atubular coupling to the bearing unit in place of the grease fitting. Thehydraulic line passed upwardly to a support secured to the mountingplate of the bracket and then extends across the conveyor above thebottom run of the belt and terminates at the stair or near side of theconveyor in a support member secured to the mounting bracket. Aconventional grease fitting is secured to the end of the hydraulic linewhich is selected to introduce minimal pressure drop.

The present invention maintains a relatively simple bearing constructionwith the rigid support of the roll on a standard sized shaft mountedwith an external re-lubrication system which may include re-lubricationfrom one side of the conveyor only. The structure of the invention canbe formed using commercially available components, the commonly acceptedidler bearing sizes, and readily understood fabrication technology.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings furnished herewith generally illustrate the best modepresently contemplated for the invention and is described herewith.

In the drawings:

FIG. 1 is a side view of a conveyor for conveying of fibrous orparticulate materials using flexible sidewall belting;

FIG. 2 is a cross section taken generally on line 2--2 of FIG. 1 andshowing how stub idlers are mounted to the conveyor frame to support thereturn side of the belting and the "one side" re-lubrication system;

FIG. 3 is a side view of the stub idler unit illustrated and shown inFIG. 1;

FIG. 4 is a front view of the stub idler unit;

FIG. 5 is a view taken on line 5--5 of FIG. 3; and

FIG. 6 is a view more clearly illustrating a grease line connectionbetween the rear and far side stub idler units.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

Referring to the drawings and particularly to FIGS. 1 and 2, the presentinvention is shown applied to support an endless flexible sidewall belt1 of belt conveyor for transport of various products 2 and particularlyfibrous, particulate and like products, as in the prior identifiedcopending application. The conveyor includes the flexible sidewall belt1 that travels about a supporting structure 3, and is shown as aZ-shaped conveyor. The conveyor sidewall belt 1 is endless and suitablysupported at its opposite ends with a drive pulley 4a and tail pulley4b. The present invention is shown applied to ahorizontal-inclined-horizontal belt conveyor for lifting and transfer ofa particulate type of material 2 from a lower level to a higher level.The belt 1 includes a flat base member 6 having similar sidewalls 7secured to the opposite edges of the belt base member. Each of thesidewalls 7 is a serpentine type of an element standing on edge andsecured to the belt to confine the material on the belt. Lateral cleats8 are secured to the belt at longitudinally spaced locations forsupporting of the material 2 on the inclined portion of the belt andinsuring transport and the upward carrying of the material. Such beltsare well known and widely used in the industry. The belt structure withthe flexible sidewall and cleats provide a relatively significant weighton the recessed portion 6a of the belt.

The intermediate length of belt 1 in the top (or carrying run) issupported by a series of spaced conventional flat idler rolls 5a whichsupport the load and maintain a particular path of travel, includingvarious horizontal and/or inclined portions, as shown. The idler roll 5ais a conventional idler roll mounted in formed bracket, and extendscompletely across and supports the base member 6. Stub idler roll units5 are constructed in accordance with this invention and are mountedapproximately 3 feet along the underside of the belt 1 to physicallysupport the belt on the recessed portions 6a of the belt 1 and tomaintain the desired location of the belt between the support frame.Each stub idler unit 5 is similarly constructed and forms the subjectmatter of the present invention.

Generally as illustrated, the structure 3 includes a longitudinalsupporting frame member extending parallel to and immediately adjacentthe outer edge of the belt 1. Each of the roll units 5 is secured to theunderside of the frame member 3. The roll unit 5 includes the tubularmounting bracket 9 secured to the underside of the frame. A rotatingroll 10 is rigidly affixed to a solid shaft 11 which extends through thebearings 12 and 13 in the mounting bracket 9. The bracket 9 is shown asa tubular member with spaced bearings 12 and 13 located and confined inan axially spaced relation within the mounting bracket 9. Bearing units12 and 13 rotationally support the shaft 11 and roll 10, with the rolllocated adjacent to the bracket 9. Lubrication of the bearing units 12and 13 is provided through the externally located fitting 17 secured inan opening in the mounting bracket 9.

In operation, the tubular bracket 9 is in the form of a post andappropriately located to establish the desired angle of orientation ofthe roll 10 with respect to the belt structure. The bracket 9 isadjustable to permit precise location of the roll 10 to the underside ofthe belt sidewall 7. In the illustrated embodiment of the invention,this permits precise orientation and location of the end face 18 of theroll 10 with respect to the adjacent belt sidewall 7. In addition andsignificantly, the bearing units 12 and 13 are located within thetubular bracket, which permits the use of a cantilevered solid shaftequal in size to the same size conventional idler, and still accept thehigh load of the belt. Likewise, bearing units 12 and 13 are close tothe location of the grease fitting 17 and can be properly and/orconveniently lubricated through the short passageway.

The stub idler roll unit 5 of the present invention can therefore bereadily and accurately installed at the necessary angle with respect tothe belt for optimum tracking. The bearings are readily and effectivelyre-lubricated. The frequency of lubrication will, of course, vary withthe application. The actual operating conditions, the environment, andthe materials being transported, will all effect the lubricationrequirements. In any event, a periodic lubrication schedule can bereadily provided for re-lubrication of the bearings and purging of theseals as required. As more fully developed herein, the system can bereadily lubricated without the necessity of the conventional highpressure lubrication equipment. In fact, a conventional low pressuresource such as a volume type grease gun is preferably used to minimizeexcessive grease pressure.

More particularly in the illustrated embodiment of the invention, thesupport frame member 3 adjacent the belt 1 is shown as a structuralchannel, and the leg of which defines a planar surface essentiallyparallel to and generally in the plane of the belt 1. The stub idlermounting bracket 9 is constructed substantially as disclosed in theabove copending application and includes a slotted mounting plate 20secured to the mounting end of the tubular bracket 9. Clamping nut andbolt units 23 which extend through the frame 3 and the slotted plate,rigidly and releasably affix the bracket 9 to the underside of the framemember 3.

The square mounting bracket 9 projects outwardly from the frame with apair of opposed sidewalls 24. The bearing units 12 and 13 are affixed inthe bearing tube 25, which, in turn, is affixed in the walls 24 forsupporting of the roll 10. The roll 10 is a drum or cylindrical member26 closed at the opposed ends by end discs 27 and 28. Each end disc 27and 28 is shown as a similar flat plate member having an inner wallportion projecting into the cylinder 26 and protruding slightlytherefrom. The outer diameter of the end disc is equal to the innerdiameter of the cylinder 26 and defines a circumferential offset areawithin which a weld 29 is deposited to rigidly interconnect the end wallto the cylinder. The weld is formed with a smooth radius to eliminatesharp edges which cause belt damage. The support shaft 11 projectsthrough the roll 10 and is firmly affixed by similar welds to each ofthe corresponding end disc.

The solid shaft 11 projects outwardly from roll 10 a short length to astepped down bearing portion 31, which serves as a locating shoulder 32.In assembly, the shaft projects through the mounting bracket 9, with theshoulder 32 abutting the adjacent bearing unit 12 and the threaded end33 extending through bearing units 13. Two clamping nuts 34 on shaft end33 abuts unit 13 and secures the roll 10 to the mounting bracket 9.Clamping nuts 34 may be replaced with a conventional castle nut andcotter key or any other unit to securely lock the stub unit in place tothe mounting bracket 9.

The bearing unit consists of a tube housing 25 with recesses at eachend, extending through the mounting bracket 9 and rigidly secured withinthe opposite walls 24 of the mounting bracket 9, as by weldments. Thebearing housing 25 is a cylindrical member having outer enlarged endbearing recesses 36. Similar bearings 12 and 13 are located in each ofthe recesses. Each of the bearings is preferably a roller bearing havingan LM11949L cone and an LM11910 cup, particularly for a five inchdiameter roll. The same structure may be used for a six inch diameterroll with an LM67048L cone and an LM67010 cup. The bearing recesses 36further include outer stop recesses 37 on the outer ends of the bearinghousing 25. Lip seals 38 and flat end washers 39 fit within the bearingrecesses 36. The washers 39 form a flat outer wall on the outer end ofthe bearing housing. In assembly, the inner flat washer 39 abuts theshoulder on the shaft and the nuts 34 abuts the outer flat washer 39 tofirmly and rigidly clamp the shaft 11 to and within the bearingassembly, thereby allowing the appropriate operating clearance for theclosely spaced bearings 12 and 13 to be accomplished during assembly.The washers 39 also serve to protect the seals from external damage.

The mounting bracket 9 and bearing housing 25 are provided with a greasechannel or passageway 40 which is fitted with the grease fitting 17. Thepassageway 14 extends radially outward essentially in alignment with thecenter of the bearing housing, and thus, chamber 16 between the bearingunits 12 and 13.

The bearing housing 25 has an inner diameter larger than the diameter ofthe bearing shaft 11 projecting through the housing. The lubricationchamber 16 is thereby formed between the housing 25 within the mountingbracket in the illustrated embodiment, the spaced bearing units 12 and13, and shaft 11 for containing lubricant. Periodically, fresh lubricantis supplied to maintain the desired lubrication and purge dirt from theseals.

The fixed fitting 17 in the bracket is adapted to receive a handoperated grease gun or other grease source for introducing oflubrication into the grease chamber between the bearings and therebyprovide a reservoir of lubricant for the bearings.

The illustrated embodiment of the invention shows a relatively simpleconstruction and support of the roll 10 in the external mountingbracket. The location of the bearing assembly within the closed mountingbracket structure minimizes the introduction of foreign material intothe bearing units. Significantly, the location of the bearing units tothe exterior establishes close location with respect to the greasefitting 17, thereby providing for a shaft diameter large enough toaccommodate the heavier bending load due to the cantileveredconstruction, while allowing the use of readily available, standardidler bearings. The short length of passageway 14 particularly permitseffective lubrication of the bearing units. Further, the bearingassembly can be lubricated using a low pressure application therebyminimizing any adverse effect resulting from high pressure applicationto the bearing seals and structure.

The re-lubrication which is necessary to establish a long operating lifeof the stub roller units is of substantial significance. The operatorcan readily provide the necessary re-lubrication at periodic intervals.The particular length of periods between lubrication will vary with theapplication and can be readily determined by the operator based on theparticular known operating conditions and loads. It is anticipated thatunder average operating conditions, a factory lubrication will beprovided and re-lubricated after approximately 3,000 to 4,000 hours ofoperation. This will of course vary with factors, such as, belt speed,material characteristics, temperature, humidity, and hours of dailyoperation, load tensions, and the like placed by the belt on the stubidler unit.

Of equal importance, is the ability of the user to reach the idler forperiodic re-lubrication by establishing the external bearing assemblies12 and 13 in the mounting bracket. The grease fitting 17 can be locatedso that it is stationary, permitting the easy addition of a flexiblegrease line 40 which permits access to the bearings from one side of theconveyor.

Referring particularly to FIGS. 2 and 6, the support structure for thehydraulic line 40 is more clearly illustrated. The hydraulic line 40terminates in the one end at the far side of the conveyor in a tubularcoupling 41 adapted to fit into the threaded grease opening in thebracket 9 and bearing housing 25 with a sealed connection. The line 40is extended upwardly along the wall of the mounting bracket 9. AnL-shaped support member 42 is secured to the mounting plate 21 by themounting bolt unit 23. The depending leg 44 of the member 42 includes anopening 45 through which the hydraulic line is passed. The line 40extends laterally across the conveyor between the conveyor framestructure and the lower run of the belt. A protective tube 46 is weldedor otherwise secured to the depending leg 44 and projects outwardlytherefrom concentric with the tube opening 45. The second end of thehydraulic line 40 at the near side of the conveyor is secured to thenear side mounting plate 21 and particularly an L-shaped support member47. The end of the line 40 is exposed to the exterior of the dependingleg 48 of member 47 and includes a standard grease fitting 49corresponding to the other grease fittings directly applied to themounting bracket 10. A tube 50 is also secured to member 47 and projectslaterally toward the far side. The tubes 46 and 50 are sized totelescopically fit anyone of various commercially available greasedtubes or conduits 51 and provides protection for the line. The tube 51is formed of rigid metal or other suitable material and cut to theproper distance between the mounting brackets on the near and far sidesof the conveyor.

The present invention thus provides a cost effective and efficient stubidler unit for flexible sidewall conveyors with construction based onuse of an existing industry standard idler shafts which simplifiesbearings replacement and minimizes repair parts stock.

Various modes of carrying out the invention are contemplates as beingwithin the scope of the following claims particularly pointing out anddistinctly claiming the subject matter which is regarded as theinvention.

I claim:
 1. A conveyor apparatus including a flat flexible sidewall belt, comprising a frame structure means for moving the flat flexible sidewall belt across said frame structure, a plurality of edge supporting stub idler units longitudinally spaced along the length of the belt and engaging the outer peripheral edge of the underside of the belt and supporting the corresponding end portion of the belt, each of said stub idler units comprising a roll and a solid shaft rigidly secured to the roll and having a shaft end projecting axially outward from one end of said roll, a shaft support unit includes a bearing housing and a pair of axially spaced support bearings within said housing and defining a lubricant chamber between said bearings, said housing located immediately adjacent said one end of said roll, said shaft end being journaled in said bearings, a lubricating passageway in said housing between said bearings and including a lubrication input connector accessible externally of aid stub idler unit and accessible with said bearing means in said housing, said support includes a tubular mounting bracket, said bearing housing secured within said bracket, said mounting bracket and said bearing housing having said lubrication passageway extending inwardly from the outermost wall of said bracket and terminating in said lubricant chamber, said housing having a corresponding bearing recess in each end with said spaced bearings located in said recesses, said recesses having a seal member abutting the bearing and a washer abutting said seal, said shaft having a shoulder abutting the washer adjacent said roll and having a threaded end extending outwardly of said tube, a clamping nut on said threaded end abutting said washers.
 2. A belt conveyor, comprising an elongated substantially flat flexible belt member having outwardly extending sidewall members, a plurality of longitudinally spaced support structures for supporting of the underside of said belt, idler stub units secured to said support structure for supporting of the outer edge portions of said belt to define a generally trough-shaped belt support, each of said stub idler units including a smooth surface cylindrical roll having opposite end closure walls and a stub shaft rigidly affixed to said ends walls and projecting axially outwardly of said roll, a rectangular tubular support post secured to said support structure in outwardly spaced relation to the outer edge of said belt, and said post including parallel spaced walls oriented in parallel relationship to the path of said belt, sealed bearings including a bearing housing secured within said mounting bracket with a separate bearing secured within said housing to the interior side of each of said parallel walls, said bearings being aligned to receive said shaft and rotatably supporting of said shaft, said mounting bracket including an adjustable mounting plate for relative fixed orientation of said roll relative to said sidewall member, said mounting plate being fixed to said post to support said shaft and roll at an angle to the plane parallel to said belt, the improvement comprising a centrally located passageway said mounting bracket and bearing housing extending inwardly from the outermost wall of the mounting bracket substantially centrally between said bearing and terminating between said spaced bearings, and a lubricant input connector secured to said passageway for selective and periodic lubrication of said bearings.
 3. A stub idler apparatus for supporting a conveyor belt, a support shaft, a roll rigidly affixed to one end of the shaft with said shaft projecting axially outwardly from said roll to an outer end, a shaft support unit including a mounting housing and a pair of axially spaced support bearing means secured within said housing and including a lubrication chamber means between said bearing means, said shaft journaled in said bearings means and having said roll located immediately adjacent to one side of said housing for projection from said housing into support location for a conveyor belt, a fixed lubricating member coupled to said lubrication chamber and accessible externally of said support unit, and said support unit including a tubular mounting bracket having an end mounting plate and a pair of parallel walls extending essentially perpendicular to said plate, said bearing housing secured to said parallel walls, a lubrication passageway in said mounting bracket and housing extending from said outer wall of the mounting bracket into said chamber, and a grease fitting secured to said passageway for selectively supplying lubricant to said bearings. 